Telephone-exchange system



C. W. KECKLER. TELEPHONE EXCHANGE SYSTEM.

APPLICATION FILED OCT. 4, 1918. 1,352,970. Patented Sept. 14, 1920.

//1 van/0r: Char/es M4 Keck/e3 UNITED STATES PATENT OFFICE.

CHARLES W. KEGKLER, OF NEWARK, NEW JERSEY, ASSIGNOR .TO WESTERN ELECTRIC COMPANY, INCORPORATED, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

TELEPHONE-EXCHANGE SYSTEM..

Specification of Letters Patent.

Patented Sept. 14, 1920.

To all whom it may concern Be it known that 1, CHARLES W. KEOKLER, a citizen of the United States, residing at Newark, in the county of Essex, State of New Jersey, have invented certain new and useful Improvements in Telephone-Exchange Systems, of which the following is a full, clear, concise, and exact description.

This invention relates to telephone exchange systems and more particularly to such systems in which link circuits are employed for interconnecting telephone lines.

In such systems it is desirable to provide means whereby the duration of telephone conversations between subscribers stations on interconnected lines may be restricted to a definite elapsed time.

It is the object of this invention to provide a system whereby a distinctive signal is given upon the expiration of a predetermined time after the response of a called station.

To attain this object in accordance with one feature of the invention, an operator and subscriber-controlled timing mechanism associated with an operators link circuit and adapted for continuous operation for a predetermined period of time, is provided with operator-controlled means for maintaining its status at'any time prior to the expiration of the predetermined period.

It is thought that the nature of the invention will clearly appear from the following specification and'the annexed drawing in which the figure shows one embodiment of the invention.

In the accompanying drawing, line circuits leading from subscribers stations A and B, which may be of any usual type, terminate in jacks 1 and 3, respectively, at a central office, at which there is provided a plurality of link circuits C, which also may be of any suitable type, only sufiicient portions thereof being shown to properly illustrate the invention. An answering sleeve relay 5 and an answering supervisory relay 6 control an answering supervisory lamp 7. Similarly, a calling sleeve relay 8 and a calling supervisory relay 9 control a calling supervisory lamp 10. Relay 9 also controls the operation of the timing mechanism which, although it may be of any suitable type, is shown as comprising a shaft 11 which is continuously rotated at a constant speed by suitable driving means, not shown.

electromagnet 12, associated with the shaft 11, 15 adapted to cause the engagement of a magnet1c d1sk 37 carried by shaft 11, and a I cooperating disk 13 mounted on a shaft 14,

maintain the arm 16, also secured to the shaft, in its normal position against a stop pin 17 removably located in a fixed plate member 18. Additional apertures 19, 20 and 21 are provided in the member 18 for the reception of the stop pin 17 for selectively varying the normal position of the arm 16. A holding pawl 23, controlled by electromagnet 24, cooperates with a ratchet wheel 25, secured to the shaft 14, for maintaining such shaft and its associated arm 16 step by step in its advancement when rotated by disks 37 and 13. A contact 26 is adapted to be closed by the arm 16 when the shaft 14 has been rotated for the predetermined time. A relay 27, controlled by the contact 26 connects an interrupter 28 in circuit with the lamp 10 to cause the intermittent lighting of such lamp, and a key 29 which although shown as a separate key, may conveniently be combined with the usual operators listening key 35, is provided for releasing relay 27. A holding key 30 removes the magnet 12 from the control of relay 9 so that the timing mechanism may be held in its advanced position by means of holding pawl 23 at any step in its progression. The timing mechanism is further controlled by a resetting key 31, which not only removes magnet 12 from the control of relay 9, but also controls magnet 24 so that pawl 23 may be removed from engagement with ratchet wheel 25 and thereby permit spring 15 to restore the arm 16 to its normal position against the stop pin 17 located in the selected aperture of plate 18.

It is thought that the invention may be more fully comprehended from the follow ing description of the operation of the system shown on the drawing.

Assuming that station A originates a call. lighting the line lamp 33 in the usual manner inresponse to the operation of line relay 32, the operator in answering the call inserts plug 34 of link circuit (1 into jack 1, thereby operating the cut-off relay 2 and the actuation of key 31 for this urpose not only causes the deenergization o magnet 12 as in the case of key 30, but also ener izes magnet 24 over a circuit extending roin battery, through the alternate contact of key 31 and the winding of magnet 24 to ground. Pawl 23 thereupon being disengaged from ratchet wheel 25, the member 13 is removed from engagement with the magnetic disk 37 and the spring 15 restores the timing position as prevlously described.

By placing the removable stop pin 17 in aperture 19, 20 or 21, which are spaced upon the plate member 18 to give proper increments, the time occupied in the rotation of arm 16 before it closes contact 26 may be varied to meet the requirements of a particular instance so that the flashing of lamp 10 will begin "upon the expiration of any desired time after the response of the called station.

It will be evident from the foregoing description that this invention affords a simple and convenient means, jointly controlled by the operator and the called station, for automatically notifying the operator upon the expiration of the time to be allotted for telephonic conversations, as well as ermitting the operator to assume contro of the timing mechanism when desired.

What is claimed is:

1. In a telephone exchange system, a plu-- continuous operation for a predetermined period, means controlled jointly by the operator and the subscriber on a connected line for starting the timing means, and operator-controlled means for holding the timing means at any time prior to the ex piration of such period.

2. Ina telephone exchange system, a plurality of line circuits terminating at a central ofiice, a plurality of link circuits thereat for interconnecting the lines, a signaling device for each link circuit controlled over a connected line to produce signals, operator and subscriber-controlled step-by-step means for causing the signaling device to produce a different indication upon the expiration of a predetermined time after the response of a called station, and operator-controlled means for holding the step-by-step means in its advanced position at any time prior to the expiration of the predetermined time.

mechanism to its normal 3. In a telephone exchange system, a plurality of lines having subscribers stations thereon and terminating ata central office, a plurality of link circuits thereat for connecting calling and called lines, a signaling device for each link circuit controlled by a called line to give certain indications, automatic means for causing the signaling device to give a different indication upon the expiration of a predetermined time after the response of the called line, and operatorcontrolled means for maintaining the status of the automatic means at any time prior to the expiration of the predetermined time.

4. In a telephone exchange system, a plurality of lines having substations thereon and terminating at a central oflice, a plurality of link circuits thereat for interconnecting the lines of callin and called stations, a supervisory relay or each link circuit jointly controlled by the operator and a called station, a signaling device controlled thereby for producing a signal upon the restoration of the receiver at the called station, timing mechanism controlled by the supervisory relay, said mechanism starting .to .operate upon the'response of the calle station, means controlled by the timing mechanism to cause a different signal to be produced by the signaling device after such mechanism has operated for a predetermined period of time, operator-controlled means or restoring the tlming mechanism to normal at any time prior to the expiration of the predetermined period, and additional operator-controlled means for maintaining the status of the timing mechanism at any time prior to the expiration of the predetermined period.

5. 'In a telephone exchange system, a plurality of lines terminating at a central office, a plurality of link circuits thereat for interconnecting the lines, a timing means for association therewith and adapted for continuous operation for a predetermined period, means controlled jointly by the op erator and the subscriber on a connected line for starting the timing means, operator "controlled means for holding the timing CHARLES W. KEGKLER. 

